1. Field of the Invention
The present invention relates to an air cleaning system and more particularly to a system which uses ultraviolet light to clean air in a vehicle such as a passenger air plane.
2. The Prior Art
Air outlets are used on commercial transportation vehicles, such as aircraft, railcars, boats, and buses, to provide passengers with a supply of moving air that they can control to improve their comfort. Typically, one air outlet is provided for each passenger location and offers the passenger options to change the volume and direction of air flow. Other conditioning of the air such as modification of temperatures, humidity, and cleanliness is performed in bulk as part of the vehicle""s centralized air handling system.
As with all centralized air handling systems that distribute recirculated air among many people, known vehicle air handling systems produce concern that pathogens supplied by one individual can be shared among the group. This concern can degrade the passenger experience, possibly even discouraging some from traveling. Concern is increased further during seasons where a large percentage of the population may be suffering from the common cold and influenza or during periods of atypical outbreaks of pathogens. The concern is especially acute in environments where air is recirculated, such as in aircraft.
It is known to use ultraviolet light to sanitize air or water and air. For example, U.S. Pat. No. 5,742,063 to Seroggins et al. shows a sterilizing unit using ultraviolet light for air ducts in the home or a building. See also, U.S. Pat. No. 5,656,242 to Morrow et al. U.S. Published Patent Application Nos. 2003/0021721 and 2003/0039576 to Hall show an air purification system for an aircraft, vehicle, office or hospital, which combines a filter section with an ultraviolet illumination section and a coating of an antimicrobial agent on surfaces in one or both of these sections.
Although a variety of air sanitizing systems using ultraviolet light are known at the present time, there is still a need for an air cleaning system that allows passengers to access a local ultraviolet air sterilization feature in a vehicle air delivery system so as to eliminate pathogens in the passenger""s dedicated air flow and that can be integrated within the mounting outlines of conventional air outlet products in aircrafts and other vehicles.
A system for cleaning air in a vehicle by ultraviolet light is provided which results in a local area in which the air contains a significantly lower level of pathogens, focused on the passenger location corresponding to that air outlet. The system is potentially helpful to clean air containing not only common pathogens, but also any pathogen which is affected by ultraviolet radiation.
In one aspect, the system includes an exposure chamber for exposure of air to ultraviolet light, an ultraviolet light source mounted in the exposure chamber and a collection plenum chamber connected to a first end of the exposure chamber. An air valve is connected to the collection plenum chamber. An expansion plenum chamber is connected to a second end of the exposure chamber and includes a plurality of passages for distribution of air to the exposure chamber. An inlet conduit is connected to the expansion plenum chamber for directing air to the expansion plenum chamber.
In another aspect, a plurality of selectively operatable subsystems are provided. Each subsystem is adapted for connection to an air delivery system. Each subsystem includes an exposure chamber, an ultraviolet light source, a collection plenum chamber, an air valve, an expansion plenum chamber, and an inlet conduit.